This invention relates generally to flat panel display devices having line cathodes and particularly to a line cathode and modulation electrode structure for use in such devices.
U.S. Pat. No. 4,121,130 shows a line cathode structure in combination with a slotted electrode. The cathode is positioned parallel to the slot and the cathode and slot lie in the plane of a space between two guide meshes along which electron beams are propagated. Electrons emitted by the cathode and travelling toward the slot pass through the slot and enter into the space between the guide meshes. Electrons which do not pass through the slot impinge on with the slotted electrode. Positioned along the cathode is a plurality of electrode pads which are arranged so that the cathode lies between the pads and the slot. By applying a positive potential to the slotted electrode and as a less positive potential to one or more of the pads, electron emission can be made to occur at selected positions along the cathode. Accordingly, the single line cathode effectively functions as a plurality of small cathodes each being controlled by a single pad.
U.S. Pat. No. 4,128,784 shows a flat panel display device having a line cathode. The cathode is positioned along a space between two parallel guide meshes along which electron beams are propagated. A series of electrodes is arranged in pairs along the cathode so that the cathode is positioned between the electrodes of each pair. The guide meshes are biased at a positive potential and the electrodes are biased more negative than the cathode. Under these biasing conditions electrons emitted by the cathode are injected into the space between the guide meshes.
U.S. Pat. No. 4,088,920 to W. W. Siekanowicz, et al. entitled "Flat Panel Display Device With Beam Guide", describes a beam guide for use in flat panel cathodoluminescent display devices. The display is composed of an evacuated envelope containing a plurality of internal support walls which divide the envelope into a plurality of parallel channels. Each channel contains a beam guide extending along one wall of the envelope. An electron gun structure emits electrons which are launched into the beam guides as electron beams. The beam guides include a pair of spaced parallel plates extending along and spaced from the backwall of the envelope. The plates contain a plurality of aligned apertures which are arranged in columns extending longitudinally along the propagation paths of the beams. Each longitudinal column of apertures constitutes a separate beam guide. The apertures also are arranged in rows transversely of the guides. One line of the visual display is generated by ejecting the electron beams out of the guide through the apertures in a single row.